Immunobiological Activities of a Newnontoxic Lipopolysaccharide From Acidiphilium GS18h/ATCC55963, a Soil Isolate Froman Indian copper mine

Bera, Rabindranath and Nayak, Abhijit and Sarkar, Chinmoy and Singh, Suman Kumar and Ratha, Jagnyeswar and Bhadra, Ranjan (2006) Immunobiological Activities of a Newnontoxic Lipopolysaccharide From Acidiphilium GS18h/ATCC55963, a Soil Isolate Froman Indian copper mine. FEMS Immunol Med Microbio, 48 (1). pp. 107-115.

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    Abstract

    A novel nontoxic lipopolysaccharide (LPS) was purified from Acidiphilium strain GS18h/ATCC55963. The chemical composition of the lipid A part of this LPS is distinctly different from that of known lipid A molecules. The LPS was investigated to determine its capacity to provide protection against toxic LPS or endotoxic shock, as has been reported for other nontoxic LPSs (Rhodobacter sphaeroides and Rhodobacter capsulatus), and also the extent and type of immunomodulatory response in terms of tumor necrosis factor a (TNF-a), interleukin-1b (IL-b), and IL-6 release as well as NO secretion by stimulated monocyte–macrophage systems. This study demonstrates clearly that mice immunized or primed with this LPS are fully protected against challenge with toxic Escherichia coli LPS. Unlike most of the extensively studied nontoxic LPSs, this LPS induced reactive nitrogen intermediates and released TNF-a, IL-b and IL-6 in both mouse and human monocyte–- macrophage systems. However, the extent of the cytokine and lymphokine releasing response was well below the range of the toxic LPS, for example that of E. coli. Owing to its capacity to provide immunostimulation of the host without causing any lethality to ensure protection against endotoxic shock, this LPS appears to have potential therapeutic value. Introduction Bacterial lipopolysaccharides (LPSs), also known as endotoxin, are capable of overstimulating the monocyte–macrophage system and are an integral part of the Gramnegative bacterial cell wall. They activate cells of the immune system that produce inflammatory cytokines, proteases, eicosanoids, and reactive oxygen and nitrogen intermediates (West & Heagy, 2002). The relationship between the chemical structure/composition and biological activity of LPS is of paramount importance to the outcome of proinflammatory cytokine production and its action. The proinflammatory cytokines produced by LPS activity are indispensable for counteracting the growth and dissemination of Gramnegative bacteria, while overproduction manifests as sepsis syndrome and endotoxic shock. The manifestation of LPS activity in biological systems is therefore under numerous controls. It depends on the species, cell type, and the structural architecture and/or compositional make up of the LPS, and may be host-protective or host-deleterious, for example by inducing hyper-toxic or shock syndrome. Biologically less active or weakly toxic lipopolysaccharides are distributed in bacteria phylogenetically not related closely to or existing distinctly from Enterobacteriaceae. The lipid A moieties of such bacterial LPSs are structurally distinct from those of the toxic lipid A owing to their sugar backbone and the fatty acid spectrum (Johnson, 1994; Rietschel et al., 1994; Zahringer et al., 1995). These types of lipid A are of particular biological interest as they lack endotoxic activity, and are capable of inducing cytokines having an entirely different spectrum and of modifying the response of toxic LPS. The LPSs originating from other sources, such as the soil bacteria Acidiphilium (Urakami et al., 1989; Kishimoto et al., 1991; Basu et al., 1994), are closely related to the Thiobacillus LPS, which is reported to be nontoxic or weakly toxic (Mayer et al., 1989). We have isolated and purified the LPS from the new Acidiphilium strain ATCC55963 (deposited in the ATCC patent FEMS Immunol Med Microbiol 48 (2006) 107–115 �c 2006 Federation of European Microbiological Societies Published by Blackwell Publishing Ltd. All rights reserved

    Item Type: Article
    URI: http://www.eprints.iicb.res.in/id/eprint/450
    Subjects: Chemistry
    Divisions: Indian Institute of Chemical Biology
    Depositing User: Mr Shyamal Nath
    Date Deposited: 01 Nov 2011 17:36
    Last Modified: 03 Feb 2012 10:33
    Official URL: htpp://dx.doi.org/:10.1111/j.1574-695X.2006.00131....
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